One reasonably correct expanded name for all human beings (creationists included), for instance, would be Eukaryote- Animal- Vertebrate- Tetrapod- Mammal- Primate- Hominid- Person (though of course we could expand it further, or choose different key groups to recognize). The beauty of such an appellation is that it expresses both what we currently are (we do have eukaryotic cells after all, as well as vertebral columns, the basic four limb skeletal structure, nipples, etc.) as WELL as who our ancestors were: the once novel and distinctive organisms from which we evolved as further sub-variants. When it comes to evolution, these two things are, in fact, by and large one and the same, which is key to understanding what common descent really implies. It’s a pity that Johnson doesn’t understand his own insight!

Indeed, creationists seem to have a knack for such accidental truisms. The classic example is the “fruit flies never evolve into non-fruit flies!” retort to the evolutionary models of speciation. What creationists clearly believe to be a knock-down argument against evolutionary theory is unintentionally a fairly deep and insightful point about it. All the descendants of some creature, no matter how much they change, are still going to be more like their ancestors than any other living thing (in part because of just the sheer unlikelihood of hitting the same distinct mix of millions of different traits twice, and in part because evolution just isn’t all THAT creative: it’s pretty darn conservative, at least compared to what we could imagine!). As such, we’ll always rightly classify them together against all other groups of organisms. We’ll probably even use the same name we once used to describe the once singular parent species. This isn’t simply some definitional chicanery either: it reflects an actual deep understanding about the nature of evolutionary change.

At one time, the earliest of mammals, finally distinct from their quasi-reptilian origins were their own distinctive species. Had some creationists back then scoffed that all their descendants were and always would “still” be mammals, they wouldn’t have known how correct they would be. Here we are, hundreds of millions of years later, and dogs, bears, gerbils, elephants, dolphins, bats and people are all “still” mammals!